Does Canned Food Cause Cancer?

Canned food has not been shown to directly cause cancer in humans, but it does expose you to chemicals that raise legitimate concern. The most scrutinized of these is bisphenol A (BPA), a compound used in the epoxy linings of most metal cans, which can mimic estrogen in the body and has been linked to cancer-promoting pathways in laboratory studies. In 2023, the European Food Safety Authority slashed its recommended safe daily intake of BPA by a factor of 20,000, signaling that earlier safety thresholds were far too generous. The gap between “not proven to cause cancer in people” and “proven safe” is where the real story lives.

What Leaches Out of Can Linings

The inside of a typical food can is coated with a thin layer of epoxy resin to prevent the metal from corroding and tainting the food. For decades, most of those coatings have been made with BPA. The problem is that BPA doesn’t stay put. It migrates into the food, especially under conditions that are routine in canned food production: high heat during sterilization, acidic contents like tomatoes or citrus, and long storage times.

A 2023 review in Food Science & Nutrition identified the major factors that increase BPA release: high temperature, high pH, long contact time, solar irradiation during storage, and the use of alkaline cleaning agents during manufacturing.¹ A separate review in Critical Reviews in Biotechnology confirmed that temperature during production, sterilization, and storage is the single most important driver of BPA migration.² In practice, this means the canning process itself, which relies on intense heat to kill bacteria, is also the step most likely to push BPA from the lining into your food.

A 2025 review looking at new EU regulations on BPA in epoxy coatings noted that the latest rules are specifically designed to reduce the leaching of BPA and its derivatives from food and beverage cans.³ That regulatory bodies are actively tightening limits tells you the issue isn’t theoretical.

How Much BPA Actually Ends Up in Your Body

Several studies have measured the relationship between eating canned food and BPA levels in urine, which is the standard way researchers track recent exposure. The most comprehensive analysis used data from the U.S. National Health and Nutrition Examination Survey (NHANES) and found that eating just one canned food item was associated with about 24% higher urinary BPA compared to eating none. Eating two or more canned items was linked to 54% higher levels. Certain foods drove the numbers up more sharply: canned vegetables and fruit were associated with a 41% increase, canned pasta with a 70% increase, and canned soup with a 229% increase.⁴

The flip side is equally telling. In a dietary intervention study, participants who switched from their normal diet to one using only fresh foods (no canned or plastic-packaged items) saw their urinary BPA drop by about two-thirds, with peak levels falling by roughly three-quarters.⁵ A more recent randomized trial, the PERTH Trial, found that each additional canned item consumed was associated with about a 14% increase in urinary BPA.⁶ The consistent picture across these studies is clear: canned food is a reliable and measurable source of BPA exposure, and reducing canned food intake measurably reduces that exposure.

How BPA Relates to Cancer in the Lab

BPA’s structure allows it to bind to estrogen receptors in the body, essentially tricking cells into responding as if estrogen is present. This matters because several common cancers, particularly breast and prostate cancer, are hormone-sensitive. In laboratory and animal studies, BPA has been shown to activate signaling pathways involved in cell growth, survival, and migration.

A review in the journal Medicine found that BPA interacts with both types of estrogen receptor and triggers changes in cell proliferation, programmed cell death, and cell migration, all of which are relevant to cancer development. At the genetic level, BPA has been linked to several pathways that promote tumor growth.⁷ A review in Frontiers in Nutrition was more specific about breast cancer, noting that preclinical data suggest a link between breast cancer risk and BPA exposure at doses below what the U.S. FDA has historically considered safe. Mechanistically, bisphenols bind to the estrogen receptor and switch on genes tied to cell proliferation.⁸

Research on breast cells from high-risk women found that low-level BPA exposure activated the mTOR pathway, a key regulator of cell growth. BPA suppressed tumor-suppressor genes like PTEN while boosting growth-promoting genes, a pattern consistent with early cancer development.⁹ In prostate cancer cells, BPA demonstrated strong binding to the androgen receptor and enhanced proliferation and invasion at very low concentrations.¹⁰ BPA exposure has also been shown to cause changes in DNA methylation patterns in animal studies, a type of epigenetic alteration that can silence protective genes or activate harmful ones.¹¹

The honest summary is this: BPA has multiple plausible mechanisms by which it could promote cancer, and the lab evidence is concerning. What we lack is a definitive human study that says “people who ate X amount of canned food got cancer at Y higher rate.” That kind of evidence is extraordinarily hard to generate, since you can’t randomly assign people to decades of high-BPA diets. The absence of that proof doesn’t mean the risk is zero; it means the science relies heavily on animal models, cell cultures, and population studies that can show associations but not iron-clad causation.

Why Regulators Are Getting Stricter

In 2015, the European Food Safety Authority set a temporary tolerable daily intake for BPA at 4 micrograms per kilogram of body weight per day. In 2023, after reviewing the accumulated evidence, EFSA dropped that threshold to 0.2 nanograms per kilogram of body weight per day, a reduction by a factor of 20,000.¹² That shift was driven by growing evidence that BPA affects the immune system at extremely low doses, in addition to its endocrine-disrupting and potential carcinogenic properties.

Under the new threshold, a large fraction of the population likely exceeds the safe daily intake from food alone. This is one reason the EU moved to implement new regulations on BPA in can coatings in 2024, mandating changes that should reduce how much BPA migrates from epoxy linings into food.³ The U.S. FDA has been slower to act but has banned BPA from baby bottles and sippy cups and continues to review its broader safety in food packaging.

The “BPA-Free” Problem

Many canned food brands have switched to BPA-free linings, which sounds reassuring until you look at what replaced it. The most common substitutes are bisphenol S (BPS) and bisphenol F (BPF), which have similar chemical structures. A molecular modeling study found that BPS and BPF both bind stably to human estrogen receptors through the same kinds of chemical interactions as BPA. BPF actually showed the strongest binding affinity of the three.¹³

Research on reproductive health found that BPS levels in the serum of infertile patients were substantially higher than BPA levels, and all three bisphenols (BPA, BPS, and BPF) inhibited the growth and function of uterine lining cells in laboratory experiments.¹⁴ The broader concern is a pattern toxicologists call “regrettable substitution,” where a regulated chemical gets swapped for a close relative that hasn’t been studied enough to be regulated yet but may carry comparable risks. A “BPA-free” label on a can doesn’t mean the lining is free of estrogen-mimicking compounds; it means it’s free of one specific one.

Beyond BPA: Metals and Processing Byproducts

BPA gets the most attention, but it’s not the only thing that can migrate out of a can. Metal packaging can also release elements like tin, aluminum, lead, cadmium, and iron into the food.¹⁵ A study of canned foods marketed in India found that levels of aluminum, iron, manganese, silicon, and tin exceeded the recommended limits set by the FAO and WHO in multiple product types.¹⁶ A study of canned tuna in Lebanon found aluminum and tin levels that, while within international safety limits, were higher than those reported in previous surveys of the same market, possibly due to poor-quality lacquer coatings on the cans.¹⁷ Tin is not considered highly toxic at the levels typically found in canned food, but high exposure can cause gastrointestinal irritation. The cancer relevance of these metals at typical dietary levels from cans is low compared to BPA, though cadmium and lead are classified as carcinogens at higher chronic exposures.

The canning process also generates processing byproducts. Furan, classified as possibly carcinogenic to humans, forms when sugars, ascorbic acid, or unsaturated fats undergo heat-driven chemical reactions.¹⁸ Because canned foods are sealed before sterilization, the furan that forms during heating can’t escape as it would from an open pot. Research on canned strawberry jam found that low pH and the type of sugar present influenced furan levels, with fructose producing more furan than glucose or sucrose.¹⁹ Furan levels in most canned foods are low enough that regulatory agencies haven’t set binding limits, but they’ve flagged it as an area for ongoing monitoring.

An emerging area of concern is microplastics. A 2024 review noted that while much past research has focused on BPA leaching from can coatings, relatively little work has examined the physical release of micro- and nanoplastic particles from those same linings and their effects on the digestive system.²⁰ This is a field in its infancy, and no firm cancer link has been established for ingested microplastics, but it illustrates that can linings are a more complex exposure source than the BPA conversation alone suggests.

Who Is Most Exposed

BPA exposure from canned food isn’t evenly distributed across the population. An analysis of NHANES data from 2003 to 2006 found that BPA levels were inversely associated with income: people with lower family income had higher BPA concentrations. The pattern was especially stark for children. Kids aged six to eleven whose families received emergency food assistance had BPA levels 54% higher than children from families who did not.²¹ This likely reflects greater reliance on canned and shelf-stable foods in food-insecure households. It also means the people least equipped to switch to fresh or frozen alternatives bear a disproportionate share of whatever risk these chemicals carry.

Practical Ways to Reduce Exposure

If you eat some canned food and are wondering what you can actually do, there are a few evidence-based steps worth knowing about.

Rinsing helps, at least a little. A study that tested hummus made from dried beans, rinsed canned beans, and unrinsed canned beans found that dried beans yielded the lowest BPA exposure. Rinsing canned beans before use produced a statistically meaningful reduction compared to using them straight from the can.²² Rinsing won’t eliminate BPA, since the food has already been sitting in contact with the lining, but it removes some of the liquid where BPA concentrates.

Choosing fresh or frozen over canned when you can makes the biggest difference. The intervention study mentioned earlier showed that three days of fresh food reduced BPA by two-thirds.⁵ Products packaged in glass jars or cartons (like some tomato sauces and soups) avoid metal can linings entirely. Frozen vegetables, which are typically flash-frozen in bags without epoxy coatings, are a practical swap that preserves most nutrients.

Avoiding heating food in the can is another common-sense measure, since heat accelerates BPA migration.² Transfer canned food to a pot or microwave-safe dish before warming it.

Canned Food Still Has Nutritional Value

It would be misleading to frame canned food as purely a hazard. Canning preserves food by using high heat to destroy harmful bacteria, which is why canned goods can sit on a shelf for years without spoiling.²³ That heat processing does degrade some nutrients, but not all. Canned tomatoes, for example, actually contain more lycopene per gram than fresh ones because the heat breaks down cell walls and makes lycopene more available. One study measured lycopene at about 3.55 mg per 100 g in canned tomatoes compared to 1.74 mg in fresh, though the bioavailability was somewhat lower for the canned version.²⁴

For millions of people, canned food is the affordable, accessible way to get vegetables, beans, fish, and fruit into their diet. The risk calculus isn’t “canned food vs. fresh organic produce,” because for many households that isn’t a real choice. It’s “canned vegetables vs. no vegetables.” A diet rich in canned fruits and vegetables almost certainly carries less cancer risk overall than a diet without them, even accounting for BPA exposure. The goal shouldn’t be to eliminate canned food in a panic but to reduce unnecessary exposure where practical and to push for better can linings industry-wide.

Phthalates and the Broader Packaging Picture

BPA isn’t the only chemical of concern in the food-packaging universe. Phthalates, a family of compounds used to make plastics flexible, also migrate into food. A review in Environmental Health found that dietary intake is the primary route of human phthalate exposure, and that food preparation and cooking processes themselves can drive phthalate migration. Everything from boiling to microwaving to frying contributes, and packaged foods show consistently higher contamination than unpackaged ones.²⁵ Phthalates are endocrine disruptors in their own right and have been linked to reproductive harm, though the cancer evidence for phthalates is less developed than for BPA.

The PERTH Trial, which randomized participants to a low-plastic diet, found that reducing overall plastic contact with food lowered both BPA and phthalate metabolites in urine.⁶ The takeaway is that canned food is one piece of a larger exposure puzzle. If you’re motivated to reduce your chemical burden from food packaging, focusing on cans alone misses the phthalates coming from plastic wrap, takeout containers, and food-processing equipment.

1
PubMed Central. Bisphenol A release from food and beverage containers – A review
2
PubMed. Food contamination from packaging material with special focus on the Bisphenol-A
3
PubMed Central. Migration of Bisphenol A and Its Derivatives From Epoxy Coatings and Demand for BPA-NI Products: Scientific Insights and Perspectives Leading to Regulation (EU) 2024/3190
4
PubMed Central. The consumption of canned food and beverages and urinary Bisphenol A concentrations in NHANES 2003–2008
5
PubMed Central. Food Packaging and Bisphenol A and Bis(2-Ethyhexyl) Phthalate Exposure: Findings from a Dietary Intervention
6
Nature Medicine. Low-plastic diet and urinary levels of plastic-associated phthalates and bisphenols: the randomized controlled PERTH Trial
7
PubMed Central. Bisphenol A and hormone-associated cancers: current progress and perspectives
8
PubMed Central. Bisphenols and Risk of Breast Cancer: A Narrative Review of the Impact of Diet and Bioactive Food Components
9
Carcinogenesis. Activation of the mTOR pathway by low levels of xenoestrogens in breast epithelial cells from high-risk women
10
PubMed. Bisphenol A promote the cell proliferation and invasion ability of prostate cancer cells via regulating the androgen receptor
11
PubMed. Oxidative Stress and DNA methylation in male rat pups provoked by the transplacental and translactational exposure to bisphenol A
12
PubMed Central. Re-evaluation of the risks to public health related to the presence of bisphenol A (BPA) in foodstuffs
13
Journal of Food Science, Nutrition and Health. Molecular docking and dynamics reveal strong binding of BPA substitutes (BPS, BPF) to human estrogen receptor alpha: implications for endocrine disruption
14
PubMed. BPA-free? Exploring the reproductive toxicity of BPA substitutes BPS and BPF on endometrial decidualization
15
PubMed Central. Review on metal packaging: materials, forms, food applications, safety and recyclability
16
Food Control. Leaching of elements from packaging material into canned foods marketed in India
17
Heliyon. Assessment of bisphenol A and heavy metals in canned tuna commercialized in Lebanon and human health risk assessment
18
Trends in Food Science & Technology. A review of the occurrence, formation and analysis of furan in heat-processed foods
19
PubMed. Effects of processing parameters on furan formation in canned strawberry jam
20
Acta Biologica Slovenica. Microplastics in Canned Food Linings and Possible Effects on Intestinal Motility: A Review of the Mechanisms and the Present Evidence
21
PubMed Central. Social disparities in exposures to bisphenol A and polyfluoroalkyl chemicals: a cross-sectional study within NHANES 2003-2006
22
Experimental Results. Effect of Rinsing Canned Foods on Bisphenol-A Exposure: The Hummus Experiment
23
PubMed Central. Effect of Hurdle Approaches Using Conventional and Moderate Thermal Processing Technologies for Microbial Inactivation in Fruit and Vegetable Products
24
Journal of the Science of Food and Agriculture. Lycopene content and antioxidant activity of fresh and processed tomatoes and in vitro bioavailability of lycopene
25
PubMed Central. Occurrence, Fate, and Reduction Measures of Phthalates in the Cooking Process: A Review